Breaker-arm for igniters.



J. E. JOHNSON.

BREAKER ARM FOR IGNITERS.

APPUCATION FILED JAN.?0. 1911.

Patented May 21,1918.

my WW um 5 w. k ww 0 M Mm UNITED STATES PATENT OFFICE.

JOSEPH EDWARD JOHNSON, 0F MERIDEN', CONNECTICUT, ASSIGNOR TO CONNECTICUT TELEPHONE & ELECTRIC COMPANY, INC., OF MERIDEN', CONNECTICUT, A CORPORA- TION OF CONNECTICUT.

BREAKER-ARM FOR IGNITERS.

Specification of Letters Patent.

Patented May 21, 1918.

1' '0 all whom it may concern:

Be it known that I, JOSEPH EDWARD J OHN- soN, a citizen of the United States of America, residing at Meriden, New I-Iaven county, Connecticut, have invented a new and useful Breaker-Arm for Igniters, of which the following is a specification.

My invention relates to improvements in so-called igniters for internal combustion engines and consists principally in improving the breaker arm construction whereby greater efficiency is obtained, particularly for high speed work. Further, the structure has advantages from the stand-point of economy of manufacture as well as durability.

In the drawings:

Figure 1 is a plan view of my improved breaker arm with certain associated parts.

Fig. 2 is a perspective view of the breaker arm relatively enlarged.

Fig. 3 is a plan view of a blank from which the breaker arm is formed.

The breaker arm when viewed from above is shown to be curved. One end thereof ismounted on a pivot 1, the other end carrying the contact point 2. 3 conventionally represents a cam, the point of which intermittently engages the arm to rock it on its pivot 1. To reduce wear the arm may be provided intermediate its length with an anti-friction roller 4. 5 represents a fixed contact point which is arranged to be intermittently engaged by the point 2, making and breaking of the contact between said oints being determined by thecam 3. 6 1s a spring which may bear against a suitable abutment 7, said spring operating in a direction to bring the point 2 against the point 5. The breaker arm S'is constructed as follows: It comprises two spaced curved or substantially C-shaped arms or side plates 88, which are integrally united at 9. The breaker arm may be made in a single piece of sheet metal blank of approximately the outline indicated in Fig. 3. This blank may have an aperture 10 for receiving the point 2 which likewise has two slotted portions 1111 adjacent to the aperture 10 so that when the blank is folded into the final form it will produce an arm, the upper end of which is skelet'onized so as to tighten the weight thereof very greatly, whereby its rapid action may be made much more certain. 12-12 are apertures in the blank which are designed to receive the pivot pin 13 for the antifriction roller 4:- At one side of the blank and on the inner border, I may also form an integral arm 14, the function of which will be later described. 15-15 are two apertures at the ends ofthe blank which may receive a bushing 16, the ends of which may be formed to properly space the side portions 88 and to hold them in the .proper relation. The arm 14 is located between the bushing 16 and the pivot pin 13 and this arm is off-set or bent so as to project across the space between the two arms 88, as best seen in Fig. 2, thereby forming an abutment to which the inner end of the spring 6 may be connected, for example, by means of a rivet 17. The spring 6 is pref erablyformed of bronze so as to constitute a good conductor and if desired this spring 6 may be reinforced or backed by a secondary spring of steel indicated at 6".

By the above arrangement the various parts may be rapidly produced and assembled for use, and in use the breaker arm may be employed with great efliciency and in high speed motors in connection with ignition apparatus for use in high speed motors. By skeletonizing the upper end of the arm, and by doing this in such a way that there is no sacrifice of strength, the arm may be very rapidly vibrated to effect with certainty the desired make and break connection when the device is used in high speed service. It will be apparent that the slotting cr perforating of the generally curved or arched breaker arm plates forms an in tegral arched truss-like structure at the outer end of the breaker arm which affords adequate strength and rigidity, at the same time so lightening the arm at the end where the greatest movement occurs that its operative speed may be increased without sacrifice of efiiciency. Another advantage resultinggifrom this construction is that by reason of the extreme lightness of the upper end of the arm the wear on the cam and contact block or roller 4 is substantially reduced, thereby increasing the effective life of the device. y

What I claim is:

1. Interrupter mechanism for high speed igniters comprising, a breaker arm of generally arched formation arranged to be piv- I otally supported at its inner end and prolongitudinally extending slot therein disposed between the edges of the arm and extendin to a point short of the contact bearing end thereof to lighten the arm and to provide a truss-like structure at the outer end thereof.

2. Interrupter mechanism for high speed igniters comprising, a breaker arm of generally arched formation comprising two rigidly connected but spaced plates arranged to be pivotally supported at its inner end-and provided with a contact bearing portion at its outer end, a longitudinally extending slot in each of said plates disposed between the edges thereof and extended to a point near the contact bearing end to lighten the arm and provide an integral truss-like structure at the outer end thereof.

3. A breaker arm for high speed igniters comprising, a pair of spaced rigidly connected curved sheet metal plates, a pivotal bearing at its inner end, said bearing serving to space said plates, a contact carrier at the outer end also operating to space said plates, a lug formed integrally with one plate and bent angularly into the space between the plates, a contact spring rigidly secured to said lug and operating to carry current and to swing said arm in one direction.

4:. A breaker arm for high speed igniters comprising a pair of spaced rigidly connected curved sheet metal plates, a pivotal bearing at one end serving to space said plates, a contact carrier at the other end also serving to space said plates, an intermediate anti-friction roller bearing substantially midway of the length of said plates, that part of each plate between said roller bearing and the contact carrier being perforated along the median line.

JOSEPH EDWARD JOHNSON. 

